Periprosthetic fractures of the hip. The role of revision arthroplasty

Abstract

In periprosthetic fractures, an exchange of the prosthesis is necessary when the prosthesis is loose (Vancouver type B2 and B3 fractures). During revision, the prosthesis can be replaced by a cemented or by a cementless stem implant. The disadvantage of a cemented stem is that cement can be forced into the fracture site and so impede union and healing. Most cementless revision stems with distal fixation are preferred because the point of fixation lies outside the area of fracture, thus allowing the fracture itself to be bridged and to be osteosynthesised with cerclage wires or cables binding the fracture pieces to the prosthesis. The stems can be implanted in two different ways. The first technique involves initial reposition of the fragments and retention with cerclage wires and then the implantation of the stem. In the second procedure, first an opening of the proximal fragment is made using an extended trochanteric osteotomy to the tip of the fracture and separation of the proximal fragment, and then the fixation zone in the distal fragment is prepared with implantation of the stem and closure of the proximal fragment around the implanted stem with cerclages. In a prospective study, the last method for the treatment of Vancouver type B2 and B3 fractures leads to reproducibly very good results with respect to fixation of the prosthetic stem, and therefore subsidence, healing of the fracture and clinical outcome. The extension of the incision and division of the proximal fragment that is an integral part of the transfemoral approach does not impair healing of the fracture or the osteointegration of the stem. This technique enables the monitoring of the positioning of the stem fixation so that the surgeon can be certain that the stem or its distal component is firmly anchored distal to the fracture, by means of a press fit. Thus, we suggest that this technique is superior to the method involving repositioning of the fracture fragments and subsequent implantation of the prosthesis stem.